Barcelona revealed two signings on deadline day, Atletico brought in a familiar face, while Juventus' Emre Can moved to Borussia Dortmund.
The Serie A clash between Hellas Verona and Genoa was pushed back as groundstaff were called into action for a painting job.
Genoa have completed deals for Mattia Perin and Valon Behrami, arriving on loan and on a free transfer, respectively.
Inter thumped Genoa on a memorable day for teenager Sebastiano Esposito, who thanked Romelu Lukaku and Antonio Conte after scoring.
Romelu Lukaku scored twice and allowed Sebastiano Esposito to mark a landmark appearance with a goal as Inter dominated Genoa.
Alexis Sanchez is among the players set to miss Inter's last game of the year, but Antonio Conte will not use absences as an excuse.
Juventus were without Miralem Pjanic and Gonzalo Higuain for their clash with Genoa, but Maurizio Sarri was happy his side got the win.
Juventus left it late to claim all three points in an entertaining Serie A clash against Genoa as Cristiano Ronaldo praised the champions.
Cristiano Ronaldo's late penalty spared the blushes of Juventus, as the 10-man champions beat Genoa.
Juventus have announced their 22-man squad to face Genoa and there is no place for injured duo Gonzalo Higuain and Miralem Pjanic.